What is the difference between TempData and Session in ASP.NET Core?
In ASP.NET Core, TempData and Session are both mechanisms for persisting data between requests, but they differ in scope, lifespan, and intended usage.
TempData:
TempData is a short-lived data storage mechanism that persists data for the duration of the current HTTP request and the subsequent HTTP request only. It’s primarily used for scenarios where you need to pass data from one action method to another during a single user request cycle.
The key characteristics of TempData include:
Short Lifespan: TempData is short-lived and only persists data for the current request and the subsequent request. After the second request, the TempData values are automatically cleared.
Controller-Specific: TempData is tied to a specific controller instance and is typically used to transfer data between action methods within the same controller.
Automatic Cleanup: TempData values are automatically cleared after being read from or at the end of the current request cycle. This automatic cleanup helps prevent memory leaks and unnecessary data retention.
Session:
Session, on the other hand, is a long-lived data storage mechanism that persists data across multiple HTTP requests and user sessions. It’s designed for scenarios where you need to maintain user-specific data across multiple requests or store session state information.
The key characteristics of Session include:
Long Lifespan: Session data persists across multiple HTTP requests and user sessions. It remains available until explicitly removed or until the session expires due to inactivity or timeout settings.
Global Availability: Session data is available to all parts of the application and can be accessed from different controllers, actions, and views within the same session.
User-Specific Data: Session is often used to store user-specific data such as authentication tokens, user preferences, shopping cart items, and session state information.
TempData is suitable for short-lived data storage needs within a single request cycle, while Session is more appropriate for long-lived data storage and user-specific data management across multiple requests and sessions.